ADVANTAGES Fast & Easy process, Time Saver: Solder-less & Crimp-less, Don't need to soldering tools ONE STEP solder and seal process for all your connections, The solders size are base on American Wire Gauge(AWG) 10-12,14-16,18-20, 22-24. Suitable to Industrial works, Home Wiring DIY, Automotive and Boat. :: QUALITY & UPGRADING Comply with all relevant international standards [CE, ROHS, ISO9001-SGS, IP67]; Based on numerous experiments by GRUDAX Electronics technical experts, get lowering the melting point of the solder, it cause to solving the problem that heat shrink shell melts before the solder. Shrinking ratio: 2:1 :: FULLY WATERPROOF IP67 & INSULATION Insulation tubing has unique Dual-Walled design [100%]: Premium quality of polyolefin tubing on the outside and hot melt adhesive inside. When heat is applied, polyolefin tubing reduces in size and adhesive flows inside the insulation. Dual walled tubing ensures waterproof seal and prevents wire corrosion. :: NO SLIP WIRE CONTACT Tubing reduces in size and solder will melt and flow through the stripped wires, ensure strong holding, the wire will *NEVER SLIP OUT* of the connector. It can be ideal used in automotive applications. :: HIGH QUALITY GUARANTEE - BOX CONTENTS We have a commitment to all buyers 100% satisfaction. Please don't hesitate to contact us if you are not satisfied with your purchase. We would try our best to assist you and ensure your satisfaction. The result of your work is important us! - Box Contents: Red=25, Blue=10, Yellow=5, White=10, Extra Heat Shrink Tubes in 6 Sizes